Start behavior

The start can be optionally made with DC braking or flying restart circuit. Moreover, an automatic start can be activated after switch-on.

Details

The start method can be selected in 0x2838:001 (P203.01). The following diagram demonstrates the different start methods:


①	Start method = "Normal [0]": After the start command, the motor is accelerated to the setpoint with the set acceleration time.
②	Start method = "DC braking [1]": After the start command, the "DC braking" function is active. Only after the hold time set in 0x2B84:002 (P704.02) has elapsed is the motor accelerated to the setpoint with the set acceleration time. DC braking
③	For demonstrating the flying restart circuit: At the time of the start command, the motor is not at a standstill (for instance due to loads with high inertia such as fans or flywheels).
④	Start method = "Flying restart circuit [2]": After the start command, the flying restart circuit is active. The flying restart circuit serves to restart a coasting motor on the fly during operation without speed feedback. The synchronicity between inverter and motor is coordinated so that the transition to the rotating motor is effected without jerk at the time of connection. Flying restart circuit
⑤	Start method = "Pre-magnetisation [3]": normal start and premagnetisation - this setting corresponds to the setting [0] normal, but adds the premagnetisation of the motor before the motor rotation begins. The premagnetisation property is generally relevant when operating in V/f motor control modes. Some asynchronous motors which have a lower stator resistance can experience high amperages when accelerating from a stopped/deactivated state. The premagnetisation property can reduce the motor current during the acceleration and is able to generate a more even acceleration curve with this motor. A property of the start method is a slight delay before the motor acceleration begins.

Automatic start after switching on the mains voltage

The automatic start can be activated in 0x2838:002 (P203.02).

Preconditions for the automatic start:

–

The flexible I/O configuration is selected: 0x2824 (P200.00) = "Flexible I/O configuration [0]"

–

For the start command, a digital input has been configured. (In case of keypad or activated network control, an automatic start is not possible.)

The following diagram demonstrates the function:


①	Start at power-up = "Off [0]": After switching on the mains voltage, a renewed start command is required to start the motor.
②	Start at power-up = "On [1]": After switching on the mains voltage, the motor starts automatically if a start command is present.

Parameter

Address	Name / setting range / [default setting]		Information
0x2838:001 (P203.01)	Start/stop configuration: Start method (Start/stop confg: Start method) – Setting can only be changed if the inverter is disabled.		Response after starting command.
	0	Normal	After start command, the standard ramps are active. – Acceleration time 1 can be set in 0x2917 (P220.00). – Deceleration time 1 can be set in 0x2918 (P221.00).
	1	DC braking	After start command, the "DC braking" function is active for the time set in 0x2B84:002 (P704.02). DC braking CAUTION! Deactivate automatic DC braking, if a holding brake is used.
	2	Flying restart circuit	After the start command, the flying restart circuit is active. The flying restart function makes it possible to restart a coasting motor during operation without speed feedback. The course between the inverter and motor is coordinated so that the transition to the rotating motor is effected without jerk at the time of connection. Flying restart circuit
	3	Pre-magnetisation	This setting corresponds to the setting [0] Normal, but adds the premagnetisation of the motor before the rotation/acceleration begins. The premagnetisation can reduce the motor current during the acceleration and generate a more even acceleration curve (by avoiding overcurrent situations). The premagnetisation function is relevant when operating in V/f motor control modes. The premagnetisation causes a slight delay before the motor acceleration begins (typically 50-200 ms, depending on motor characteristic).
0x2838:002 (P203.02)	Start/stop configuration: Start at power-up (Start/stop confg: Start at powerup)		Start behavior after switching on the mains voltage.
	0	Off	No automatic start after switching on mains voltage. In addition to the inverter enable, a renewed start command is always required to start the motor.
	1	On	Automatic start of the motor after switching on the mains voltage if the inverter is enabled and a start command exists.